In a conventional color TV bulb, the shadow mask is formed from 0.006" thick low carbon steel sheet. Flat stock is blanked out in a stamping operation. A photo-sensitive resist is applied to both sides of the flat sheet and the resist is exposed to light through a negative photo-mask. The exposed portion of the resist reacts to light in a known manner (i.e. as a positive) to allow etching of holes or slots from both sides of the sheet. The resist patterns applied on each side are identical in spacing, but may differ in size. Often the holes on one side of the mask are slightly larger. After acid etching, the flat sheet is formed by a stamping operation into a specific cylindrical or spherical shape for the panel. A frame is attached to the mask and the structure is annealed. The forming operation introduces enough deformation into the hole pattern to cause each mask to be unique.